This is the only backup plugin I've found that actually does everything I want from a backup plugin:

1) back up both database and files
2) automatically email backup (even if they are large)
3) also send backups to dropbox (this isn't essential for me, but nice to have)

The only downside is that there are quite a few typos about the place (which doesn't inspire too much confidence in there not being any in the code) and that the whole thing is a little too complex and daunting for a beginnger (there are LOTS of options which almost put me off, but I persevered and just left things as default and everything seems to work fine :) ).